In the petitions, Société Mondiale, a vehicle of distressed debt tycoon Nelson Tanure, cited a number of disparate reasons for creditors led by Aurelius Capital Management LP to be declared abusive, a designation that could lead to them being barred from restructuring proceedings.

Among those reasons is that Aurelius bought debt it holds in Oi for a fraction of its face value, and is seeking to gain unusual profits from the current dispute, Societe Mondiale said. The fund also said that the Aurelius group’s attempt to put forth a plan of its own at a creditors meeting scheduled for Dec. 19, rather than deliberating on plans put forth by the board, represents a conflict of interest.

“The bondholders led by Aurelius are making a hostile takeover attempt, participating in blackmail, among other measures,” Société Mondiale said in a statement after filing the documents with the court.

A representative for bondholders affiliated with Aurelius declined to comment.

In November, the judge overseeing the Oi bankruptcy case, the largest ever in Latin America, effectively removed Oi’s board from ongoing debt renegotiations.

The petitions on Tuesday represented the second attempt by Oi’s board to regain power. Last week, Société Mondiale, which controls the board through alliances, asked Brazil’s telecommunications regulator to prohibit the company from signing any contract that would imply a transfer of control to Aurelius.

Oi, which filed for bankruptcy protection a year and a half ago, is wracked by divisions between creditors, the board, and management.

Aurelius is spearheading a group of creditors known as the International Bondholders Committee, which is in turn part of an alliance of funds and banks holding about 22 billion reais ($6.79 billion) of Oi’s debt.

Earlier on Tuesday, a U.S. judge reiterated previous judgments, saying the fight over Oi’s future must be fought in Brazilian courts.

The International Bondholders Committee has been attempting to establish jurisdiction for some restructuring proceedings in the Netherlands, which has more creditor-friendly bankruptcy law than Brazil. ($1 = 3.24 reais) (Reporting by Gram Slattery; Editing by Jonathan Oatis)